package com.hdl.school.utils;

public class StringUtil {
    public static String padNum(String num,int len){
        String newStr=num+"";
        while (newStr.length()<len){
            newStr="0"+newStr;
        }
        return newStr;
    }

    public static String padNum(int num,int len){
        return padNum(String.valueOf(num),len);
    }
    public static String padNum(long num,int len){
        return padNum(String.valueOf(num),len);
    }
}
